Beam-induced heating in the TOTEM Roman Pot detectors at the LHC

During 2011, temperature increase has been observed in the TOTEM Roman Pots installed in the LHC (sector 45) while the proton beams were circulating in the accelerator ring. The warming up has been recorded with the detectors in standby mode and in absence of the active detector cooling which would have guaranteed a constant operational temperature of about -25°C. This effect, induced by beam coupling impedance, is a critical issue for the operation of the Roman Pots and needs to be quantified in detail. This note describes the results of the analysis carried out on the temperature data measured in the TOTEM RP up to the maximum total beam intensity of 1.9 × 10^14 p/beam which is the limit reached by LHC in 2011 using 50ns-spaced proton bunches. Finally, the data presented here allows estimates of the maximum temperature that could build up in the detectors at LHC nominal beam intensities (25ns-spaced bunch trains).